1. Field of Art
The present invention generally relates to the field of integrated semiconductor circuits, and more specifically, to exchanging configuration data between devices using a bi-directional communication channel.
2. Description of the Related Art
DisplayPort is an industrial standard of digital interface between two or more devices. Commonly, a DisplayPort interface controls transfer of video and/or audio from a source device, such as a graphics processing unit (GPU) or graphics adapter, to a sink device, such as computer display or other display device. DisplayPort uses two channels, a Main Link and an Auxiliary Channel (AUX-CH) to communicate data between the source device and the sink device. The Main Link serially transmits video, audio and other secondary data at a first rate while the AUX-CH carries management and device control data for establishment or configuration of the Main Link at second rate which is slower than the first rate. Generally, the source device initiates transmission of data through the AUX-CH, allowing the source device to modify Main Link characteristics, although the sink device may prompt modification of the Main Link by sending an interrupt request (IRQ) to the source device via the AUX-CH.
However, other digital interfaces may also be used for interfacing a source device and a sink device. For example, a High Definition Multimedia Interface (HDMI) or a Digital Visual Interface (DVI), may be used to exchange information between the source device and the sink device. Hence, devices used for interfacing the source device and the sink device generally support communication of different types of management and device control data, such as the DisplayPort Interface, HDMI, DVI or other digital interfaces. For example, Display Data Channel (DDC) protocols are commonly used for communicating supported display modes from a display to a GPU or for communicating adjustments to display parameters, such as brightness or contrast, from a GPU or graphics adapter to a display device. To support a variety of devices which may use different protocols, it is beneficial for an interface between different devices to support data exchange using different protocols. However, conventional approaches to supporting different protocols typically use individual connections associated with each protocol for data transmission, increasing the size and complexity of a device.